U.S. patent number 3,986,373 [Application Number 05/591,045] was granted by the patent office on 1976-10-19 for drive system for a laundry apparatus.
This patent grant is currently assigned to The Maytag Company. Invention is credited to John D. Goodlaxson.
United States Patent |
3,986,373 |
Goodlaxson |
October 19, 1976 |
Drive system for a laundry apparatus
Abstract
A drive system for a laundry apparatus including a torque
sensing drive mechanism for determining the presence of washing
fluid in the cavity of a rotary positive displacement pump by means
of the different resistive torque responses of relatively full and
empty pump cavities. A clutch mechanism joins two driving pulleys
that are belt-connected to two driven pulleys on the transmission
and pump units. The presence of washing fluid in the pump cavity
effects separation of the driving pulleys and actuates only the
pump unit. Absence of washing fluid in the pump cavity causes the
driving pulleys to remain coupled and a centrifugal extraction
operation is initiated through the transmission and spin
clutch.
Inventors: |
Goodlaxson; John D. (Colfax,
IA) |
Assignee: |
The Maytag Company (Newton,
IA)
|
Family
ID: |
24364813 |
Appl.
No.: |
05/591,045 |
Filed: |
June 27, 1975 |
Current U.S.
Class: |
68/23.7; 68/208;
192/94 |
Current CPC
Class: |
D06F
37/40 (20130101) |
Current International
Class: |
D06F
37/30 (20060101); D06F 37/40 (20060101); D06F
023/04 (); D06F 037/40 () |
Field of
Search: |
;68/23.7,184,208
;192/94 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Coe; Philip R.
Attorney, Agent or Firm: Ward; Richard L.
Claims
I claim:
1. In a laundry apparatus for performing a washing operation and a
liquid extraction operation, the combination comprising: means for
performing said washing and extraction operations including a tub,
a fabric basket within said tub, and agitation means within said
fabric basket; conduit means connected to said tub for conducting
liquid from said tub to an external drain; pump means communicating
with said conduit means and operable for pumping liquid from said
tub to said external drain during said extraction operation; driven
means operable to effect said washing operation including operation
of said agitation means and to effect said extraction operation
including high speed rotation of said basket; a motor including a
drive shaft and operable for driving said driven means and said
pump means; control means controlling the operation of said motor
during said washing and extraction operations; and drive means on
said motor drive shaft and operable for selectively driving only
said pump means for a period of time to effectively remove fluid
from said tub during said extraction operation before said driven
means is operable for effecting rotation of said fabric basket,
said drive means including clutch means responsive to the
substantial removal of fluid from said tub for effecting a driving
connection to said driven means while continuing the driving of
said pump means.
2. A laundry apparatus as described in claim 1 wherein said drive
means includes a first pulley rotatable with said motor shaft for
driving said pump means and a second pulley rotatable with said
first pulley through said clutch means for driving said agitation
means and effecting rotation of said fabric basket.
3. In a laundry apparatus for performing a washing operation and a
liquid extraction operation, the combination comprising: means for
performing said washing and extraction operations including a tub,
a fabric basket within said tub, and agitation means within said
fabric basket; conduit means connected to said tub for conducting
liquid from said tub to an external drain; pump means communicating
with said conduit means and operable for pumping liquid from said
tub to said external drain during said extraction operation; driven
means to effect said washing operation including operation of said
agitation means and to effect said extraction operation including
high speed rotation of said basket; a motor including a drive shaft
and operable for driving said driven means and said pump means;
control means controlling the operation of said motor during said
washing and extraction operations; drive means including clutch
means on said motor drive shaft and including first and second
pulleys; and means for drivingly connecting said first pulley to
said pump means and said second pulley to said driven means, said
drive means being operable for drivingly connecting said first
pulley to said drive shaft for rotation therewith and to maintain
said second pulley drivingly disconnected from said drive shaft to
effectively remove fluid from said tub without effecting rotation
of said basket, said clutch means being further operable to effect
rotation of said second pulley with said first pulley and drive
shaft responsive to the substantial removal of fluid from said tub
whereby said pump means is operable for effectively removing fluid
from said tub during said extraction operation before said driven
means is operable for effecting high speed rotation of said fabric
basket.
4. A laundry apparatus as described in claim 3 wherein said second
pulley is drivingly disconnected from said drive shaft during at
least a portion of the cycle responsive to a predetermined
resistive torque on said first pulley to effect rotation of only
said first pulley.
5. In a laundry apparatus for performing a washing operation and a
liquid extraction operation, the combination comprising: means for
performing said washing and extraction operations including a tub,
a fabric basket within said tub, and agitation means within said
fabric basket; conduit means connected to said tub for conducting
liquid from said tub to an external drain; pump means communicating
with said conduit means for pumping liquid from said tub to said
external drain during said extraction operation; driven means
operable to effect said washing operation including operation of
said agitation means and to effect said extraction operation
including high speed rotation of said basket; a motor including a
drive shaft and operable for driving said driven means and said
pump means; control means controlling the operation of said motor
during said washing and extraction operations; drive means
including clutch means on said motor drive shaft and including
first and second pulleys; and means for drivingly connecting said
first pulley to said pump means and said second pulley to said
driven means, said drive means being operable for drivingly
connecting said first pulley to said drive shaft for rotation
therewith and for maintaining said second pulley drivingly
disconnected from said first pulley and said drive shaft responsive
to a predetermined resistive torque on said first pulley, the
resistive torque on said first pulley being a function of the
quantity of liquid in said pump means and being at least as high as
said predetermined resistive torque with washing fluid in said tub
and being less than said predetermined resistive torque with the
washing fluid substantially removed from said tub whereby said pump
means is operable for effectively removing fluid from said tub
during said extraction operation before said driven means is
operable for effecting rotation of said fabric basket.
6. A laundry apparatus as described in claim 5 wherein said clutch
means includes adjustable spring means for maintaining a biasing
force on said clutch means for effecting engagement of said first
and second pulleys when said resistive torque is less than said
predetermined resistive torque.
7. In a laundry apparatus for performing a washing operation and a
liquid extraction operation, the combination comprising: means for
performing said washing and extraction operations including a tub,
a fabric basket within said tub, and agitation means within said
fabric basket; conduit means connected to said tub for conducting
liquid from said tub to an external drain; a reversible motor
operable in a first direction and in a second reverse direction;
rotary positive displacement pump means communicating with said
conduit means and operated by said reversible motor for pumping
toward said tub when said motor is rotated in said first direction
during said washing operation and for pumping liquid from said tub
to said external drain when said motor is rotated in said reverse
direction during said extraction operation; driven means rotatable
in said first direction to effect said washing operation including
operation of said agitation means and rotatable in said reverse
direction to effect said extraction operation including high speed
rotation of said basket, said reversible motor including a drive
shaft and operable for driving said reversible driven means and
said pump means; control means controlling the operation of said
motor during said washing and extraction operations; and drive
means including clutch means, a first pulley for drivingly
connecting said drive motor to said pump means, and a second pulley
for drivingly connecting said drive motor to said driven means,
said first pulley being rotatable with said motor drive shaft while
said second pulley is nonrotatable with said motor drive shaft
responsive to a predetermined resistive torque on said first
pulley, said second pulley being rotatable with said first pulley
in the absence of said predetermined resistive torque, the
resistive torque on said first pulley being a function of the
liquid in said pump means and being at least as high as said
predetermined resistive torque with washing fluid in said tub and
being less than said predetermined resistive torque with the
washing fluid substantially removed from said tub.
8. A laundry apparatus as described in claim 7 wherein said clutch
means includes a helical member fixed to said motor drive shaft and
on which said first pulley climbs to a stop upon encountering a
resistive pump torque load greater than said predetermined
resistive load, said clutch means being operable to effect
disengagement of said first and second pulleys until the resistive
torque of the pump is less than the said predetermined resistive
torque.
9. A laundry apparatus as described in claim 7 wherein said rotary
positive displacement pump means comprises a turbine style pump
operable for developing resistive torque to effect disengagement of
said first and second pulleys and the removal of fluid from said
tub without rotating said basket.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a drive system and more particularly to a
drive arrangement for sensing, through resistive torque, the
presence of washing fluid in the cavity of a rotary positive
displacement pump.
2. Description of the Prior Art
The prior art shows a continuing search for a system that senses
the tub water level and provides a means of lowering the level
prior to a period of high speed extraction. Previous work in the
appliance field shows systems that disclose electrical or pressure
systems for sensing this water level. These systems are used in
conjunction with slip clutches or solenoid actuated clutches which
are energized, when the water level is reduced to a predetermined
level, to activate the extractor. Also shown in prior art is a
system that uses a pump for both drain and agitation. In this prior
art pump system, a slip clutch is arranged so that the fabric
basket will gradually come up to extraction speed as the fluid
level in the tub is lowered by pumping out.
SUMMARY OF THE INVENTION
It is an object of the instant invention to provide a drive system
for a laundry apparatus that will sense the presence of washing
fluid in the tub by the resistive torque on the rotary positive
displacement pump.
It is a further object of the instant invention to provide a drive
system for a laundry apparatus that will allow engagement of the
pump alone during at least the initial portion of the pump out
operation.
It is a further object of the instant invention to provide
automatic pump out of fluid from a laundry apparatus prior to
effecting centrifugal extraction of liquid from fabrics in the
laundry apparatus.
Briefly, the instant invention achieves these objects in a drive
system for a laundry apparatus that includes a motor-driven drive
mechanism and associated drive means selectively operating a rotary
positive displacement pump and a centrifugal extractor
transmission.
Operation of the system and further objects and advantages thereof
will become evident as the description proceeds and from an
examination of the accompanying three pages of drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings illustrate a preferred embodiment of the invention
with similar numerals referring to similar parts throughout the
several views wherein:
FIG. 1 is an overall view of an automatic washing machine with
various components broken away to show portions of the drive system
incorporating the instant invention;
FIG. 2 is a top view of the drive mechanism taken along Lines 2--2
of FIG. 1 with a portion of the spring cover broken away to show
the torque opposing springs;
FIG. 3 is a sectional view of the drive mechanism taken along Lines
3--3 of FIG. 2; and
FIG. 4 is a sectional view of the pump taken along Lines 4--4 of
FIG. 1.
DESCRIPTION OF A PREFERRED EMBODIMENT
Referring to FIG. 1 there is shown an automatic washing machine
including a base frame 10 supported on a plurality of adjustable
legs 11 and mounting a cabinet comprising a sidewall 13 and a top
cover 14. The top cover 14 includes a hinged panel comprising an
access door 15 normally covering a recessed loading opening 16 and
movable to an open position to permit access through the opening
16. The top cover 14 further includes an upwardly extending housing
19 for accommodating various control members such as programming
means actuatable by a dial 20.
The washing machine is provided with controls for programming the
machine through a sequence of operations including energization of
the motor 33 for operation in a first direction to effect a washing
and/or rinsing function followed by energization of the motor 33 in
a second direction to effect a liquid removal function.
Mounted within the cabinet is a tub assembly 21 nutationally
supported on the base frame 10 by an inverted tripod arrangement
including tub braces 23 which are connected at the lower end to a
support member 24 positioned on and movable relative to a dome
portion of the base frame 10. The tub braces 23 are connected at
their upper ends to a generally imperforate outer liquid container
or tub 25. The tub braces 23 are also resiliently connected to the
base frame 10 by means of centering springs 26 which resist
rotation of the support member 24 relative to the base frame 10 but
permit nutational movement relative to the base frame 10.
Revolubly mounted in the imperforate outer tub 25 is a perforate
clothes basket or fabric basket 29 in which is positioned an
oscillatable agitator 30 for effecting movement of the fabrics and
washing fluid within the tub assembly. The imperforate outer tub 25
and the perforate inner fabric basket 29 are substantially aligned
with the loading opening 16 in the top cover 14 for permitting the
operator to place articles within the fabric basket 29 and remove
them upon completion of the cycle.
The base frame 10 also supports through a motor mount 31 the
reversible drive motor 33 which is operable in a bidirectional
drive system for selectively effecting oscillation of the agitator
30 or centrifugal rotation of the inner fabric basket 29.
As generally shown in FIG. 1, the base frame 10 also supports the
pumping means that is driven by the motor 33. The pump 61
communicates with the outer tub 25 through the conduit 63 and is
operable for pumping liquids from the outer tub 25 toward an
external drain when the motor 33 is operated in the direction for
effecting centrifugal extraction. Since the pump 61 is drivingly
connected to the bidirectional motor 33 and is operable in the
first and second directions with the motor 33, the pump 61 will
tend to pump liquid toward the outer tub 25 through the conduit 63
when the motor 33 is operating in the direction for effecting
agitation of the fabrics during the washing portion of the
cycle.
The drive mechanism 34 mounted on the shaft 37 of the drive motor
33, as best shown in FIGS. 2 and 3, consists of several elements: a
hub 41, a set screw 43, a pump drive pulley 44, an agitate-spin
drive pulley 45, clutch disks 46, a roller thrust bearing 49, a
retaining ring 50, a spring cover 51, springs 53, ball bearing 55,
drive pins 59 and an adjustment screw 54. The hub 41 attaches the
drive mechanism 34 to the drive motor shaft 37 by means of the set
screw 43 engaging a flat portion of the motor shaft 37. The outer
surface of the hub 41 includes a four start external buttress
thread 56 which engages with a like internal thread on the pump
drive pulley 44. The roller thrust bearing 49 is located between
the underside of the pump drive pulley 44 and the first of the
clutch disks 46. This bearing 49 absorbs the end thrust present
when the clutch is fully engaged as in agitation. The preferred
embodiment shows an uneven number of clutch disks 46 which are
alternately keyed to rotate either with the hub 41 or with the
agitate-spin drive pulley 45. In the embodiment shown, the
preferred number of disks 46 is seven. An even number of disks 46
will cause the roller thrust bearing 49 to run when the clutch is
disengaged. The agitate-spin drive pulley 45 has a ball bearing 55
pressed into its inner diameter. This pulley-bearing assembly 57 is
secured to the hub 41 by the retaining ring 50.
Two drive pins 59 are pressed into the top surface 58 of the pump
drive pulley 44, spaced diametrically apart, and are at an angle
less than perpendicular to the pulley top surface 58. These pins 59
provide a connecting point for one end of the torque opposing
springs 53 with the other end of the springs 53 fastened to
downwardly projecting ears 60 on the spring cover 51. These torque
opposing springs 53 can be adjusted to a predetermined setting by
rotating the spring cover 51 relative to the hub 41 and the pulley
top surface 58 with a tool and locking the cover 51 to the hub 41
with the adjustment screw 54. These springs 53 oppose the
disengaging of the pulleys so that light driving torque as with an
empty pump will not disengage the clutch, thus enabling both
pulleys to drive. Heavy pump resistive torque as with a full pump
will effect disengagement of the pulleys and allow driving of only
the pump pulley.
As generally shown in FIG. 1, the drive system for effecting
operation of the agitator 30 and rotation of the fabric basket 29
includes the drive mechanism 34 on the shaft 37 of the drive motor
33. This drive mechanism 34 has agitate-spin pulley 45 and pump
pulley 44 with the agitate-spin pulley 45 drivingly engaged with a
main drive belt 35 which in turn is drivingly engaged with the main
drive pulley 36 under predetermined conditions of the drive
mechanism 34. The main drive pulley 36 is drivingly connected to
either the agitator 30 through a drive shaft 39 and the gearing of
a transmission 40 or to the fabric basket 29 through the drive tube
38 and housing of the transmission 40 and a spin clutch (not shown)
depending on the direction of rotation of the motor 33. The pump
drive pulley 44 is drivingly engaged with a pump drive belt 47
which in turn is drivingly engaged with the pump pulley 48 for
driving the pump pulley 48 under predetermined conditions of the
drive mechanism 34 to initiate a pump out.
Operation of the motor 33 in a first direction effects rotation of
the main drive pulley 36 for effecting oscillation of the agitator
30 through the drive shaft 39 and transmission gearing. In this
direction of rotation, the pump drive pulley 44 is rotated down the
hub helix, fully engaging the clutch disks 46, effecting rotation
of both pump pulley 48 and main drive pulley 36, thereby
simultaneously effecting the pumping of washing fluid toward the
tub 25 and oscillation of the agitator 30.
Operation of the motor 33 in the opposite direction will effect
either a pump out or a high speed extraction operation dependent on
whether or not there is any fluid in the tub 25. If there is fluid
in the tub 25, the resistive torque of the fluid in the pump cavity
64 will cause the two drive pulleys to separate and only the pump
drive pulley 44 will turn thus initiating a pump out. As the
resistive torque diminishes, the pulleys will again be joined
through the clutch mechanism and the centrifugal extraction
operation will begin. The pumping means is preferably a rotary
turbine type pump having positive displacement characteristics such
as the turbine pump 61, as shown in FIG. 4, since a centrifugal
pump will not provide the resistive torque required for
disengagement of the clutch mechanism to provide a pump out prior
to centrifugal extraction.
It is therefore seen that the instant invention provides clear and
distinct advantages over the drive systems shown in the prior art.
The pump out or drain operation is automatically achieved prior to
centrifugal extraction without a separate motor being required.
Because of the automatic drain operation, the fabrics being washed
are allowed to settle to the bottom of the fabric basket prior to
centrifugal extraction making balancing of the basket less
critical. If the pump 61 should become blocked while water remains
in the tub, this drive system will not allow the machine to begin
the extraction operation therefore eliminating the possibility of
overflowing the top of the tub. If the timer knob is manually
advanced past the first part of the extraction period, this drive
system will sense the presence of water in the tub and give a pump
out prior to centrifugal extraction. Also, the drive motor is not
required to accelerate the fabric basket to extraction speed in a
full tub of water.
In the drawings and specification there has been set forth a
preferred embodiment of the invention and although specific terms
are employed these are used in a generic and descriptive sense only
and not for purpose of limitation. Changes in form and proportion
of parts, as well as the substitution of equivalents, are
contemplated, as circumstances may suggest or render expedient,
without departing from the spirit or scope of this invention as
defined in the following claims.
* * * * *